The objectives of the Indianapolis Center for Sickle Cell Disease are: To screen approximately 6,000 individuals in the metropolitan area per year and to provide appropriate education and counseling to individuals found to have a hemoglobinopathy. To educate the professional and lay public for better understanding of sickle cell disease. To conduct research in the following areas: 1. a study linkage between the Hb locus and other genetic markers. 2. the clinical significance of Hb isoalleles. 3. phagocytic and opsonic function in patients with sickle cell disease.